I found UserTesting.com but it costs $40 per person which is super expensive. I want to test if I am communicating the correct message to users on our site. Where is a good place to do some hallway testing? Or does it have to be in-person?

Try Starbucks testing*

Approach them right after they bought a coffee and ask them:
"You just bought a coffee. Can I buy you a muffin and get two minutes of your time for a quick feedback on my website?"

Ask your questions and make them talk as much as possible without influencing them

Get inspired by the answers and find out if your message works

The last question, especially if the message/site didn't work well, is to explain the intention and ask them what they would have understood better. But only do this as the last thing, don't get into a debate take the comment with a grain of salt.

*I call this Starbucks testing because it works especially well in coffee houses where people are relaxed and spending some leisure time. Often they're open to talk. It might be different in other countries or cultures. I think key success factors are that they get a little reward for their time investment and to make them understand that you won't be trying to sell something.

If you want to learn more about user testing I'd suggest Rocket surgery made easy by Steve Krug - an enjoyable and entertaining read.

I have never used them and I don't know precisely how much analysis usertesting.com provides but you have to realize that setting a test up involves some real work and having a platform to do it so quickly seems very valuable. The users themselves also have to spend time testing your website and deserve a reward so that $40 is actually super cheap. In fact, simply recruiting users through a consumer panel with some minimal targeting (i.e. including the incentive but without the cost of the test/interview/recording) cost more than that where I am now. Why would you think usability testing should be virtually cost-free and you could get useful feedback from multiple people without effort?

Regarding hallway usability testing, the whole point is to quickly test a product with whoever you can find in the hallway (hence the name), typically colleagues, perhaps friends or family. The idea is to compromise on the quality of the sample to be able to gain some quick feedback even if a regular usability test is not practical for you. It does not have to be anything but it's usually in-person, if only because looking for actual users and setting up a remote usability test does in fact require more effort.

If you're new to usability testing, and want to do something cheap and effective, I would recommend that you read Rocket Surgery Made Easy by Steve Krug

It's a very good introduction to running cheap in-person usability tests. Has the added bonus of being quite a thin book too. I'm sure your local library could help find a copy if you don't want to buy one.